What is Autoimmune Encephalitis (AE)?

Autoimmune Encephalitis is a fatal disease where the body’s own immune system starts mistakenly attacking the brain, which leads to many problems including inflammation in the brain and impaired function. Autoimmune encephalitis (AE) is a complex medical condition which usually needs collaboration of doctors from multiple specialties, such as neurologists, psychiatrists, rheumatologists, immunologists etc. for effective treatment. With prompt diagnosis and the right treatment, there is good chance of recovery for many autoimmune encephalitis patients; however, not all the patients will have complete recovery. The mortality rate in Autoimmune Encephalitis is around 6% and some patients never regain their body and brain function. For a good prognosis, it is important to get immediate diagnosis and treatment started in patients where autoimmune encephalitis is suspected. If autoimmune encephalitis or AE is diagnosed early, then treatment can also be started early; and early and aggressive treatment increases the chances of quick and complete recovery for the patient.

Cause of Autoimmune Encephalitis (AE)

The exact cause in majority of the patients with Autoimmune Encephalitis is not clear. Some of the probable causes and triggers of autoimmune encephalitis include:

Teratoma, which is a type of tumor usually developing in the ovaries. This is found only in very few patients with autoimmune encephalitis.

Cancer in the patient indirectly triggers an autoimmune response which is known as paraneoplastic syndrome. This can be a trigger factor in a minority of the patients with autoimmune encephalitis.

If the patient gets exposed to some type of bacteria, such as mycoplasma or streptococcus then also it can lead to autoimmune encephalitis. There may or may or not be an active infection.

Symptoms of Autoimmune Encephalitis (AE)

Patients suffering from autoimmune encephalitis (AE) experience a spectrum of neuro-psychiatric symptoms. Diagnosing autoimmune encephalitis based on the symptoms is quite challenging, as patients tend to have different symptoms at different times with different levels of intensity; because of which autoimmune encephalitis can be confused or misdiagnosed with other diseases. Initially patient may have either psychiatric or neurological symptoms, which further makes the diagnosis difficult. Some of the common symptoms of autoimmune encephalitis include:

If the patient has unexplained combination of the above neuro-psychiatric symptoms, then it is a good indication that they are from autoimmune encephalitis.

Diagnosis of Autoimmune Encephalitis

Tests are done to detect the antibodies which can cause Autoimmune Encephalitis. If the test for autoimmune antibodies is negative, it still does not definitely rule out Autoimmune Encephalitis, as unknown antibodies can also cause autoimmune encephalitis or it can also be caused by known antibodies for which diagnostic tests are still not available for detecting them.

MRI scan can be done which shows inflammation in the brain (encephalitis). EEG test helps in detecting the seizure activity in the brain. These tests help in ruling out the exclusive psychiatric causes for the patient’s condition.

Treatment for Autoimmune Encephalitis

The treatment for autoimmune encephalitis has developed over the past many years and has many treatment options. For the best possible outcome of autoimmune encephalitis, it is important that early and aggressive treatment is started, as early and aggressive treatment helps in preventing the progression of autoimmune encephalitis.

The treatment is divided into “first line” and “second line” treatment options. The doctor may prescribe more than one first-line treatment for the patient. The four commonest first-line treatments for autoimmune encephalitis include:

If there is a Teratoma present, which is triggering the autoimmune response, then it is removed.

Plasmapheresis is done for removing the harmful antibodies present in the blood.

Steroids, which will decrease the immune response and inflammation, are prescribed.

Intravenous immunoglobulin (IVIG) therapy is started which is thought to fill up the binding sites where the harmful antibodies get attached to the brain cells.

If there is no improvement with first-line treatment for autoimmune encephalitis, then the patient is started on second-line treatment, which comprises of immunosuppressants which will suppress the immune system. The three commonest immunosuppressants used as second-line treatment for autoimmune encephalitis are:

Rituximab.

Cytoxan (cyclophosphamide).

CellCept.

Benzodiazepines are prescribed for treating other symptoms of autoimmune encephalitis like sleeplessness and agitation. Lorazepam prescribed in high dose is also effective in such cases. Anti-psychotic drugs, which are used to treat schizophrenia and bipolar disorder, may not be effective and in some cases can worsen the symptoms of autoimmune encephalitis. If there is no response to anti-psychotic medications, then it helps with the diagnosis that the autoimmune encephalitis may be causing the psychosis in the patient.

Many patients, after recovering from an acute episode of autoimmune encephalitis, may experience symptoms of traumatic brain injury, which comprise of difficulty in concentrating, Acquired Attention Deficit Disorder, fatigue, coordination problems, cognitive challenges, memory problems, change of personality, lack of motivation, depression and irritability. Aggressive treatment of these symptoms helps a lot in improving the results, particularly, in young individuals, who have a lot of brain plasticity. It is recommended that the patient continues with traumatic brain injury rehabilitation after getting discharged from the hospital.

If the patient still has persistent neurological symptoms, then it is an indication that the underlying disease, which is autoimmune encephalitis is still continuing. In such cases, it is important to continue treatment with immunomodulation medicines on an outpatient basis.

Recovery from Autoimmune Encephalitis

The process of recovery from Autoimmune Encephalitis is different and unique for each patient. As mentioned numerous times previously, early diagnosis with early and aggressive treatment is the best path to sooner recovery from autoimmune encephalitis. According to studies, about half of the patients with autoimmune encephalitis have substantial improvement within a month of starting treatment and continue to show improvement after getting discharged from the hospital. More than half of the patients with autoimmune encephalitis will slowly have partial or complete recovery, but the average duration for recovery from autoimmune encephalitis is about 14 months.